[Intel-gfx] [PATCH v2] drm/i915: Simplify and fix object to display tracking

[Tvrtko Ursulin]

On 03/31/2015 01:32 PM, Chris Wilson wrote:
> On Tue, Mar 31, 2015 at 01:23:10PM +0100, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> Purpose of this tracking is to know when to flush the cache between the
>
> CPU and the
>
>> non-coherent display engine. Previously to:
>
> s/Previously/Prior/
>
>>
>>     commit 121920faf2ccce9aa66a7e2588415c9647b66104
>>     Author: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>     Date:   Mon Mar 23 11:10:37 2015 +0000
>>
>>         drm/i915/skl: Query display address through a wrapper
>>
>> This worked by a mix of direct flag manipulation and checking for
>> existence of a pinned GGTT VMA.
>>
>> With the introduction of rotated display mappings this approach is
>> no longer correct.
>>
>> New simpler approach is to just keep this count over calls which pin and
>> unpin objects to and from display.
>
> at the slight cost of extra space in every bo.

Is space is a concern, how about just a flag then? Counter kind of lost 
its usefulness at the moment.

>>
>> (Inspired and extracted code from a larger rework by Chris Wilson.)
>>
>> v2: Remove the limit since it is not well defined.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>
> Proof reading someone else's changelog is much simpler than coming up
> with one from scratch.
>
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

Thanks!

Tvrtko